Mounting for abrasive segments



Oct. 24, 1939. H. P. KIRCHNER MOUNTING FOR ABRKSIVE SEGMENTS 4 Sheets-Sheet 1 Filed 'Feb. 9, 1938 Jzy. 2, I

| I l I 1 1 I L l' 1 INVENTOR. HENRY P KIECHNEE ATTORNEY.

Oct. 24, 1939.

H. P. KIRCHNER MOUNTING FOR ABRASIVE SEGMENTS Filed Feb. 9, 1938 4 Sheets-Sheet 2 INVENTOR. HENRY P K I ECHNER ATTORNEY.

Oct. 24, 1939. K RHN R 2,177,549

MOUNTING FOR ABRASIVE SEGMENTS Filed Feb. 9,1938 4 Sheets-Sheet s lllljllll INVENTOR. HENRY P. K\RCHNER ATTORNEY.

Oct. 24, 1939. H. P. KIRCHNER 2,177,549

MOUNTING FOR ABRASIVE SEGMENTS Filed Feb. 9, 1938 4 Sheets-Sheet 4 INVENTOR. HENRY P. NRCHNER ATTORNEY.

Patented Oct. 24, 1939 PATENT oFFicE MOUNTING FOR ABRASIVE SEGMENTS Henry P. Kirchner, Niagara Falls, N. Y., assignor to The Carborundum Company, Niagara Falls,

N. Y., a corporation of Delaware Application February 9, 1938, Serial No. 189,643

7 Claims.

This application relates to apparatus for the manufacture of wood pulp, and relates more par-v ticularly to means for mounting the abrasive seg ments which constitute the grinding elements of a large pulp wheelor a segmental wheel for other purposes.-

Abrasive segments are now quite generally used in the construction of large pulp'wheels on account of thedifficulties connected with the construction of monolithic pulp wheels having an outer diameter of four to five feet and axial dimensions of a similar order of magnitude. These segments are made from granular material of great hardness such as fused alumina which is bonded, for example, by means of a mixture of clay and a flux, the whole mix containing abrasive particles and bond cured by heating to a temperature such that a strongly bonded segment is formed on cooling to ordinary atmospheric temperatures. These segments constitute large masses of bonded abrasive whose coefiicients of thermal expansion differ greatly according to the nature of the constituents and according to the method of the curing of the bond. One of the objects of the present invention is to provide a strong mounting for each segment so that it may be strongly anchored to a metaldrum which in turn is supported on a concrete or cement core. Another object of the inventionis to provide a construction in which defective segments can be replaced in the locality where pulp is being ground without the necessity of sending the whole wheel back to the factory.

The improved means for mounting abrasive segments in accordance with the present invention are illustrated in the accompanying drawings in which:

Figure 1 is a partial'side view of a segmental pulp wheel constructed in accordance with the invention; v

Figure 2 is a plan view of a base plate for an abrasive segment, the view being directed toward the surface of the plate on which an abrasive segment is subsequently to be mounted;

Figure 3 is a section on the line IIIIII of Figure 2;

Figure 4 is a side view of the base plate shown in Figure 2; Figure 5 is a sectional elevation of a clamping member used to clamp an abrasive segment on the base plate shown in Figures 2, 3 and 4, the section being taken on the lineVV of Figure 6; Figure 6 is a side view of the clamping member shown in Figure 5; p

Figure 7 is a section of an abrasive segment and of a portion of its mounting including a steel mounting ring, the section being taken in a plane that passes through the axis of the wheel;

Figure 8 is a view showing a portion of the periphery of an abrasive annulus, with the underlying support indicatedby means of broken lines;

Figure 9 is a fragmentary View of a modified mounting for the abrasive wheel, the view being taken in the direction of the axis of the wheel;

Figure 10 is an elevation, viewed in a direction perpendicular to the axis and partly in section,

showing an abrasive Wheel consisting of a plurality of annuli, each of which contains a plurality of abrasive segments, the section being taken in an axial plane of the wheel, and the mounting being similar to that shown in Figure 1;

Figure 11 is an elevation of a segmental abrasive wheel showing the driving connection through terminal driving'fianges;

Figure 12 is a perspective view of one of the pins used for connecting a segmental base plate to a rotatable support;

Figure 13 is a section of an abrasive segment and of an annular support, showing a modified .form of mounting, the section being taken in a plane that passes through the axis of the wheel;

Figure 14 is a section taken on the line XIV-XIV of Figure 13;

Figure 15 is a section of an abrasive segment taken in a plane similar to the plane of the section in Figure 13, the method of attaching the segment to its support being modified; and

Figure 16 shows the base of the abrasive segment illustrated in Figure 15.

Referring to the drawings in detail, there is shown in Figure 1 a plurality of abrasive segments 2, each of which is mounted on a base plate 3 with the aid of a T-shaped clamping member 4. The base of each segment is provided with a T-shaped slot 6 into which the clamping member '4 is inserted, a resilient packing I being used to protect the shoulders 8 of the abrasive segment fromdirect contact with the clamping member 4. The packing layer 7 can be made, for example, of such materials as Babbitt metal, or resinoid cement, or Portland cement, or of a mixture of litharge and glycerine. A similar packing can be inserted at 5 between the base of each abrasive segment and the adjacent base plate 3. The clamping members 4 can be drawn toward the shoulders I by means of screws 9 which have threaded engagement with the clamping member 4, while the enlarged heads of the screws press against shoulders I!) which are indicated in Figure 3 on the base plate 3, the stem of the screw 9 passing through an opening II in the base plate.

Each segment is thus firmly secured to a base plate before it is placed in position in assembling the wheel.

When a sufficient number of abrasive segments have been provided with base plates, they can be assembled on a rotatable support which will now be described. Each base plate 3'is provided with flanges I2 having openings I3 for a purpose which will be described later.

In Figure 7 a mounting ring I4 is shown. This ring can be made from a hollow steel cylinder or annulus I5 which is provided with outwardly projecting flanges I6 and (if desired) an inwardly projecting member ll. These flanges are welded on to the annulus I5. The flanges I6 are provided with openings I8 of the same size as the openings I3 in the flanges l2.

In mounting an abrasive segment 2 with its" base plate 3 on the mounting ring I4, the flanges I2 of the base plate are placed outside (measured in an axial direction) of the flanges I6 of the mounting ring, so that openings I3 in the baseplate register with corresponding openings IS in the flanges I6. Pins I9 are then each driven through four aligned openings, namely through an opening I3 in abase plate, through an opening I8 in the adjacent flange I6, through an opening I8 in asecond flange It on the opposite side of the ring, and finally into a second opening I3 in the same base plate. The pins fit snugly into the openings I3 and I8 so that some force isrequirecl to makethe pin I9 fill the four aligned openings. Other base plates with attached segments are added in a similar manner, the joints between the segments being filled with a packing material which is sufficiently yielding to permit circumferential expansion or contraction of the segments as a result of changes of temperature. A suitable packing for these joints between abrasive segments can be made, for example, by impregnating two sheets of fabric with reactive synthetic resin and ,forming a composite packing layer of the desired thickness and consisting of two resin impregnated sheets separated by. means of a vulcanizable rubber composition. The layered sheet thus formed is heated to harden the synthetic resin in the outer layers of fabric and to vulcanize the intermediate rubber composition. A sufficient number of layered sheets made in a manner similar to that just described are placed between the segments to fill tightly the gaps between adjacent segments. Instead of having the layered sheets contact with the surfaces of the abrasive segments, a self-hardening resinous cement can be used in directcontact with the segments and one or more layered sheets (of the kind whose manufacture has been described) used to complete the joint between any two adjacent segments. After an annulus, composed of abrasive segments and their attached base plates, has been completed on a mounting ring I5, other similar annuli can be constructed and brought together with the first anulus to form a segmentalwheel of the desired length. The joints between adjacent segments of different annuli can be biased as indicated in Figure 11.

The wheel isprovided with a reinforced concrete center 2! which extends from the mounting rings IE to center bushings 22 and 23. These bushings surround the arbor hole 24 through which the drivingshaft 25 passes. Torque can be transmitted from the driving shaft to the wheel by means of terminal driving flanges 26 which have TQSPQQ- tive right-hand and left-hand threaded engagement with the driving shaft.

Reinforcement is provided for the concrete core in the form of a steel cage containing a plurality of turns 27 in the outer part of the core and another series of turns 28 situated nearer the arbor hole. These turns are connected (using welded connectives for example) by means of steel rods. 29 which have a direction approximately parallel to the axis and by means of radial rods 3|.

A modified form of connection between an abrasive segment and its supporting base plate is illustrated in Figure 9. Each segment 2 is attached to its supporting base plate 3 by means of a plurality of cast metal keys 35. These keys can be made, for example, by pouring Babbitt metal into dovetail grooves which are formed in I9 in the manner described above for the form.

of mounting illustrated in Figures 1 to'8 inclusive. This form of mounting has the advantage that the grooves or slots in the base of the abrasive 1 segment (into which the metal is poured) do not penetrate far into the interior of the segment.

the metal keys are distributed over a large area, thus reducing the danger of breakage which arises from the localized pressures on small areas that occur in certain types of clamps. I

In the case of the clamping means illustrated in Figures 1 to 8 inclusive, the T-shaped clamping member 4 contacts'with a resilient or yieldable packing I which transmits the pressure to a thick shoulder 8. The distances from the pressure areas, (to which the clamping pressure is applied by the head of the T-shaped clamp) measured toward the sides of the segment are also comparatively large. Suitable packing material can also be introduced between the base of the segment 2 and the base plate 3.

The mounting ring and base plates are provided as described above with flanges I6 and I2 which interconnect (with the aid of the force-fitted pins) the ring with the baseplates- When the ring, the flanges, and the plates are made of suitable metals, these interconnected members form a structure of considerable radial thickness which is desirable in View of the large centrifugal and working stresses in pulp wheels.

When it is desired to replace a segment, the pins I9 which connect the base plate with the mounting ring have to be removed. For this pun pose one of the ends of a pin is provided with a threaded hole 3!]. Where the segment to be replaced is located at one end or the other end of the wheel, a suitable tool (having a stem with a thread corresponding to that of the terminal opening in the pin) can be screwed into the pin, and force can be exerted on the head-of thetool to draw out the pin. If the segment to be replaced is not an end segment, one or more segments in the same row as the injured segment can be removed in order to obtain access to the pins which hold the base plate of the injured segment to the mounting ring. It is possible, however, to make the openings I3 and I8 and the The contacts between the abrasive segment and stems and suitable clamping means.

corresponding pins larger for the end annuli than for the interior 'annuli. The pins may be drawn, for examplafrom an end segment by means of a tool which engages athreaded opening 30 in the end of each pin. After a terminal pin has been removed, a smaller tool can be inserted into a threaded opening of a pin in an adjacent interior segment, said opening being made accessible by the removal of the outer larger pin. The pins from an interior segment can thus be withdrawn without removal of the outer segment which isprovided with the larger pin openings. It is possible, in this manner, to facilitate the removal of an interior segment without removing the adjacent outer segment that has just been referred to.

In the modified form of mounting illustrated in Figures 13 and 14 nuts 32 are embedded or anchored in holes or grooves 33 in the base of a segment 2. This can be done for example by clamping the segment 2 with the holes or grooves 33 opening vertically upward. The nuts 32 are then mounted in proper position within the openings 33 by means of threaded Liquid material such as sulphur, Babbitt metal, or lead is hen poured into the openings 33 around the nuts 32. After the cast material has hardened sufliciently by cooling, the threaded stems and the clamps are removed. The segment 2 can then be clamped on its base plate 3 by means of bolts M. The segment 2 and the attached base plate 3 are then attached tothe support M by means of pins in the manner previously described in connection with Figures '7 and 10.

In the case of the methodof mounting illustrated in Figures 15' and 16 the grooves 33 in the base of the segment 2 are filled with a material which possesses great mechanical strength on hardening subsequently to the casting operation. The castings 36 are then drilled and threaded. The segment 2 is then attached to its base plate by means of bolts as in the method of mounting illustrated in Figures 13 and 14.

A number of the advantages of the improved pulp Wheel will be apparent to those skilled in the art. Modifications of the structure described are possible without departing from the invention which is defined within the compass of the following claims.

I claim:

1. A pulp grinding wheel element comprising a bonded abrasive segment'which has a longitudinal T shaped slot in its base, a metal base plate for supporting the base of the segment, one or -more flanges on said base extending inwardly to- Ward the axis of the wheel from the surface which contacts with the segment, a T-shaped clamping member whose head is supported on internal shoulders of the abrasive segment formed by said slot, and one or more screws extending through the base plate and engaging the clamping member so that the clamping member can be pressed against the internal shoulders of the abrasive segment by turning the screw head in contact with the base plate to hold the segment firmly against the base plate.

2. A pulp grinding wheel comprising a reinforced cement center, a mounting ring supported by said center and having one or more annular flanges extending radially outwardly therefrom, a plurality of base plates for abrasive segments disposed outside said mounting ring and having one or more radially inwardly extending flanges, a plurality of abrasive segments each supported on one of said base plates, segment supporting means including a T-shaped clamping member whose head is supported on internal shoulders of the abrasive segment and whose stem is accessible through a slot in the abrasive segment, a screw whose head contacts with one side of said base plate and whose stem extends through an opening in the same into threaded engagement with said T-shaped clamp, and torque transmitting means comprising a plurality of force-fitted pins each of which passes through one or more mounting ring flanges and also through one or more base plate flanges.

3. A pulp grinding wheel element comprising an abrasive segment having a plurality of grooves in the surface which is to be attached to its support, a base plate for supporting said abrasive segment and having a plurality of grooves each of which is connected with one of said grooves in the abrasive segment, a plurality of metal keys formed by filling pairs of said connected grooves with molten metal and cooling the same, and means for connecting each of said base plates along with its attached abrasive segment to a rotatable support, said means comprising an annular flange extending radially inwardly from the base plate and a second annular flange extending outwardly from said rotatable support adjacent to the first flange in the same radial zone and pins extending through corresponding openings in the first mentioned flange and in the second flange.

4. A pulp wheel comprising a plurality of abrasive segments each of which has a plurality of grooves in its base, a base plate adjacent to the base of each abrasive segment and having grooves which connect with corresponding grooves in the abrasive segment to form keyways, a plurality of keys connecting each base plate to its corresponding segment and formed by casting metal in said keyways, a hub on which said base plates are mounted in close succession around the periphery of the hub, and driving pins each of which is tightly fitted into a pair of registering openings disposed respectively in said base plate and in said hub, said openings in each pair being formed respectively in a flange that projects inwardly from a base plate and in a flange that projects outwardly from the hub.

5. A pulp wheel comprising a plurality of abrasive segments each of which has a plurality of grooves in its base, a base plate adjacent to the base of each abrasive segment and having grooves which connect with corresponding grooves in the abrasive segment to form keyways, a plurality of keys connecting each base plate to its corresponding segment and formed by casting metal in said keyways, an annular support on which said base plates with segments keyed thereto are mounted in close succession around the periphery of the support, said support being in the form of an annular ring which is anchored in a concrete center, and driving pins each of which is tightly fitted into a pair of registering openings disposed respectively in said base plate and in said annular support.

6. In a segmental wheel an abrasive segment having a threaded insert cast in its base, said insert increasing in cross-sectional area from a minimum at the segmental base to a maximum in the interior of the segment, a base plate for supporting said segment, a bolt that passes through said base plate and engages said threaded insert for clamping said segment to its base plate, a rotatable support for said base plate and attached segment, an annular flange projecting radially inwardly from said base plate, an annular flange projecting outwardly from said support so as to radially overlap in adjacent position said projection from the base plate, and a pin closely fitted in registering openings in said support and in said base plate.

7. In a segmental wheel an abrasive segment having one or more nuts embedded in the base of the segment, the nuts being embedded in one or more grooves in which the width increases from a minimum width at the base of the seg- 'ment to a maximum width in the interior of the amuse said base plate and attached segment, an annular flange projecting radially inwardly from said base plate, an annular flange projecting outwardly from said support so as to radially overlap in adjacent position said projection from the base plate, and a pin closely fitted in registering 10 openings in said support and in said base plate.

HENRY P. KIRCI- INER. 

